How can you start making more money than what is necessary for family to leave ?
What is the formula for the income and what are the opportunities to make extras ?
How do you get a better flat as well ?
You get $5 for each entrance correctly resolved. There are some other bribes that appear in the game, people asking for letting them through, it is probably worth $5 extra which means that if you can afford to have a warning you get a profit of one extra person. I never took them so I do not know what are the consequences.
You get $200 extra for letting the soldier's girlfriend through, you get some extra cash if you manage to adopt your niece (something like $150 -> $200) and another $200, if you properly help the Ezic order. The $1000 gift from the order gets you in trouble so either burn it or be ready to have all your money confiscated. If the latter happens, you can sort it out by letting the right Ezic agent through but the they will not return the money for you.
I just finished a game where I escaped on the 22nd, with my wife and my son and living in a class 7 apartment. The flats are offered for you throughout the game, not sure if at specific dates. You can manage moving to another apartment and paying for bills and what not if you can get about 12~14 entrances sorted out per day.
Hope this helped and good luck!
I just finished the game with over $1200. You simply let most of your family die off (saving money on food and making it cheaper to escape) and never upgrade apartment. Make sure you save your guard mate and let his lady in (extra $100 for that) and take bribes wherever possible. Also never take the booth upgrades (these are of little use anyway) and process around 12-14 people a day (an easy average once you get the hang of it). Also detain wherever possible once you start getting the detention bonus, until then just reject them as this is quicker.